Till now, for measuring the angular distribution of a fuel jet ejected from a fuel injector, the fuel injector was usually arranged above a two-dimensional field of catch containers that are each allocated to only one measuring coordinate and detect a partial spray quantity in a predetermined collecting area around the measuring coordinate. The catch containers are provided, for example, with a graduation, which is read off manually, or each of the catch containers is connected to a separate sensor, which electronically measures the partial spray quantity collected by the catch container. On the side facing the fuel injector, the catch containers are provided with a funnel-shaped enlargement having a, for example, square boundary so that the catch containers can be abuttingly arranged side by side in a matrix-like manner. The measurement of ejected fuel quantities by accumulation in an inspection glass is described, for example, in the introductory description of German Patent No. 195 16 923.
The above-described measuring device and the appertaining measuring method have the disadvantage that a separate catch container having a separate sensor has to be provided for each measuring coordinate. If the intention is to provide a resolution in an equidistant grid of 15 measuring coordinates in the two plane coordinate directions, then the measurement at a total of 225 measuring coordinates is required. This requires 255 catch containers having 225 separate sensors. In this context, it must be considered that the sensors must be calibrated among themselves to make an objective and accurate measurement possible. This requires considerable outlay and places limits on an improved resolution of the measurement.
It is also disadvantageous for the catch containers to be arranged in a plane collecting surface. When working with relatively large spray angles, the lateral offset of the catch containers with respect to the vertical spray direction is relatively large. This relatively large lateral offset limits the measurement of relatively large spray angles. Because of the long spray paths in the case of large spray angles, the measuring results are corrupted, for example, by gravitation and a deceleration of the spray jet by the ambient air. Therefore, the measurement of the angular distribution of the fuel jet in the range of large spray angles using the conventional device and the conventional method is unsatisfactory and inaccurate.